My colleague Sal Spada wrote an article on new developments in the additive manufacturing space. Additive manufacturing, also called 3D printing, involves joining materials to make objects from a 3D model, usually layer upon layer. In contrast, much traditional manufacturing has been subtractive; Lathes, saws, and boring tools cut materials down to make a product.

There has been some breathless coverage of 3D Printing’s impact on the supply chain. In the supply chain realm is has been speculated that additive manufacturing could be able to transform the spare parts supply chain. The idea is that instead of carrying a plethora of slow moving parts across a network of warehouses, these warehouses could just manufacture the parts as needed.

That is not to say additive manufacturing in warehouses is widespread. ARC estimates that approximately 75-80 percent of additive manufacturing applications are for rapid prototyping. The final 20-25 percent of applications include: producing manufacturing tooling and molds and dies, enabling trial production runs, and for end-use parts – including spare parts manufacturing.

What kind of spare parts will be produced using additive manufacturing? According to Sal, it has become “relatively easy to build a solid business case for using additive manufacturing to produce complex, high-value parts for which small order quantities are required.”

Further, additive manufacturing does not require as many machines, or as much floor space. “A part normally produced in multiple production steps may now be manufactured using a single piece of production equipment. It is also possible to consolidate multiple features/parts into a single part with additive manufacturing.” This means, many spare parts warehouse would have sufficient space available to engage in 3D printing. In fact, once slots formerly used to house inventory are eliminated, they could end up with much more available space.

Other positive developments include new material formulations in metal powders and plastic polymers that are being commercialized. These new inputs “allow additive manufacturing of finished parts with mechanical properties comparable to or better than those possible with traditional production methods.” In addition, there is the introduction of hybrid machines specifically for metal based printed parts that allow additive and subtractive processes to be combined. Additive is used mainly to build up the product and subtractive is more for the final finish.

But one challenge for many manufacturers has been that manufacturers do not have the internal expertise or a well-defined process to objectively evaluate a spare part’s suitability for additive manufacturing. But Sal is seeing progress here is well.

TCS, for example, has a business justification analysis service. This consulting is based on a set of clearly delineated steps they have developed to evaluate a part’s suitability for additive manufacturing. This domain expertize has been incorporated in a knowledge-based decision support system. This tool gathers input from the customer regarding the part and produces a metric that ranks the part’s suitability for additive manufacturing.

According to Sal, “Inputs to the tool include the complexity of the desired part, the surface finish, whether it will need post-process finishing on a subtractive machine, and just how closely the final part will need to match desired tolerances. Also assessed are part quantity.”

“The tool uses this information to generate a numerical assessment of the suitability of the part, coded either red (not suitable with current technology), amber (not the best candidate, but could be redesigned to be more suitable), or green (qualifies as a candidate). With the above data, this preliminary assessment takes only around 30-45 minutes to perform.”

In summary, the use of additive manufacturing is still not very widespread at spare parts warehouses. But it is clearly more feasible than it was just a few years ago.